In the magazine’s new ratings released Monday, the Seahawks lead the NFL and are trailed by the rival San Francisco 49ers in second, the Green Bay Packers in third, the Houston Texans in fourth and the Chicago Bears in fifth.

While SI’s Doug Farrar noted that the Seahawks have a big question mark at defensive end and the pass rush, he also noted the issue should resolve itself as the season continues. Chris Clemons (knee) and Cliff Avril (hamstring) could return within Seattle’s first few games, and Bruce Irvin is slated to return Week 5 after serving his PED suspension.

Here’s what Farrar had to say about Seattle’s No. 1 defensive ranking:

The Seahawks ranked first in the NFL in points allowed in 2012, and fourth in yards allowed. Head coach Pete Carroll and general manager John Schneider have put together a young, aggressive defense based on press coverage and speed to the line of scrimmage. Carroll is the real mastermind here, and he’s taken the front packages he learned from Monte Kiffin long ago and expanded them into concepts tailored for today. Seattle runs a lot of what looks to be Cover-1 in a four-man front, but that can change pretty quickly. Former defensive coordinator Gus Bradley (and his replacement, Dan Quinn) will run packages that include 3-4 and 5-2 fronts with alternating safeties and single-linebacker sets.

That said, this defense wouldn’t work without the best cornerback duo in the league. If Richard Sherman isn’t the NFL’s best cover corner, he’s on a very short list. Sherman has perfected the art of disrupting a receiver’s timing by pressing off the line, and he’s as good in trail coverage down the sideline as anyone you’ll see. Opposite Sherman is CFL veteran Brandon Browner, who prefers a sledgehammer to his compatriot’s finer tools. Browner plays like a safety at the line — he loves to hit, not just press — and he’s excellent in short coverage.